Permanent finishes for cellulosic articles



United States Patent 3,276,885 PERMANENT FINISHES FORCELLULOSIC ARTICLES93, 4 Claims. (Cl. 106205) The present invention relates to newpermanent finishes for cellulosic articles such as paper, cotton,cellulose fabrics, etc. More particularly, the cellulosic finishesaccording to the invention comprise at least one polysaccharide andglyoxal.

Still more particularly, the polysaccharide is notably constituted bygalacto-mannite.

Gu-ar flour, extracted from guar seeds, is a special polysaccharideconstituted by units of galactose and mannose; it is galacto-mannite.

In order to obtain the finishing product according to the invention,there is first prepared an aqueous colloidal solution of galacto-mannitein which glyoxal is dissolved. The cellulose article to be treated iscoated with this solution and then dried, preferably by heat. Withoutthe applicant being bound by or restricted by a theory, it is suggestedthat there is then produced a condensation reaction between the glyoxaland the galacto-mannite on the one hand and between the glyoxal and thecellulosic support on the other.

The colloidal glyoxal solution of galacto-mannite possesses remarkableproperties. In the first place it has an excellent stability as long asit is not applied on the cellulosic supporting surface, it can thereforebe stored indefinitely before use, irrespective of its concentration inactive product, that is to say in glyoxal. In solutions of the sameconcentration made from ordinary amylaceous materials such as starches(industrial and domestic), etc., glyoxal generally produces immediatecoagulation, which practically excludes the utilization of suchsolutions.

When the said glyoxal colloidal solution of galactomannite is applied tothe cellulosic support, there is produced, even in the cold state, adouble condensation reaction of the glyoxal which is much more intensein the hot state. It would appear that the glyoxal first reacts with thecellulosic material of the support and that this reaction, by anapparent catalytic effect, causes a condensation reaction with thegalacto-mannite. This would explain the stability of the solution in theabsence of the support and the profound chemical transformation whichtakes place in the presence of the cellulosic support.

From the practical point of View, the result is that the cellulosicsupport is not simply coated with a film of the coating product but ischemically combined in a fundamental manner, through the intermediary ofthe glyoxal, with the galacto-mannite. 1

Thus, for example, it is possible to obtain with a paper or a cardboard,a remarkable performance in respect of resistance to water, a highresistance to penetration by fats, and exceptional printing qualities.

In the case of cellulose fabrics, there are obtained finishing effectswhich are very resistant to washing, that is to say extremely permanentsuch as: a better feel to the touch, and improvements in starching andnon-creasing properties. 7

In carrying out the method according to the invention, thegalacto-mannite is dissolved in water in order to obtain a colloidalsolution of suitable concentration, for example, of the order of to 50grams per liter. Then the glyoxal is dissolved in the solution, takingfor example a commercial glyoxal hydrate in the form of solidpoly-hydrate or Patented Oct. 4, 1966 in the form of a solution, or, ifdesired, in the form of crystallized glyoxal hydrate, according to theeffect desired, between 1 and 50 grams of glyoxal per 100 grams ofgalacto-mannite.

The cellulosic support is coated with this solution in a suitablemanner, for example, at the rate of 0.1 to 5 grams of dry material persquare metre of paper or of fabric.

The condensation is then effected, if so desired, by simply drying atordinary temperatures, but preferably by heating, for example, atbetween 50 and 150 C., and preferably at about 100 C.

According to a particular feature of the invention, in order to carryout the condensation, catalysts may be added, such as weak acids orsalts of an acidic nature. In order to obtain a good water resistancefor paper to water, salts of zirconium and zinc may also be used, forexample, in the proportion of 1% of salt with respect to the drymaterial.

In order to make the invention more readily under.- stood, two examplesof its application will be given below by way of indication only andwithout any implied limitation.

' Example 1 An aqueous solution of galacto-mannite is prepared at 25grams per liter, and in this solution is dissolved a quantity ofcommercial glyoxal corresponding to 5 grams per liter of 100% glyoxal.This solution is used to coat a whitened or bleached kraft paper of 65grams per square meter, at the rate of 2.5 grams of dry material persquare meter of paper.

The coated paper is then heated to 100 C. for one minute.

There is thus obtained a paper, the resistance of which to Water hasbecome remarkable, whereas it had practically no resistance at allbefore the treatment.

The resistance to water was determined by the Jacobsen test, whichconsists of subjecting test pieces of identical dimensions, immersed forhalf their length in water at 20 to a constant tension, and measuringthe time which elapses between the immersion of each test piece and itsrupture at Water level.

In the above case, the Jacobsen test gave 565 seconds for the papertreated in accordance with the method of the invention, against 0 secondfor the same paper untreated, 12 seconds for a paper treated with thegalactomannite solution without addition of glyoxal and 0 second for thepaper treated with the glyoxal solution not containing anygalacto-mannite.

The effect of resistance to water of the treated paper remainedpractically unchanged after a series of successive immersions in water,followed by drying at 100 C.

Similar results 'were obtained with papers or cardboards of all kinds,for example with straw paper for corrugating, with various kraft papers,with imitation sulphurized papers, etc.

With an imitation sulphurized paper for example, treated in accordancewith the principle of the invention, the resistance to the penetrationof fats is practically doubled as compared with an untreated sample(test using butyl Carbitol).

Example 2 An aqueous solution of galacto-mannite is prepared at 25 gramsper liter, in which solution there is dissolved a quantity of commercialglyoxal corresponding to 2.5 grams per liter of 100% glyoxal. A cottonfabric is coated with this solution at the rate of 7 grams of drymaterial per square metre of fabric. The fabric is then heated at forone minute.

There is obtained an uncreasable and stiffened (fabric. These effectsare permanent, that is to say they remain It will furthermore beunderstood that the present in- I vention has been described only in apurely explanatory manner and without any implied limitation whatever,and that any useful modification may be made thereto. without departingfrom its scope. Thus, in particular, the main ingredients of the finishaccording to the invention may be previously mixed in powdered form, andthe appropriate quantity of water can then be added at the time of useof the finish. In consequence, therefore, the finishing productaccording to the invention can be readily stored either in thecompletely prepared form (in view of its stability) or in the form of adry mixture of its solid ingredients.

I claim:

1. A permanent finish for cellulosic materials consisting essentially ofan aqueous solution of colloidal galactomannite having a concentrationbetween 5 and 50 grams per liter of solution and a proportion of glyoxalin said solution between 1 and 50 grams of 100% glyoxal per 100 grams ofgalacto-mannite.

2. A permanent finish for cellulosic materials consisting essentially ofan aqueous colloidal solution of 5-50 gms. of galacto-mannite per literof solution, 1-50 gms.

of 100% glyoxal per 100 gms. of galacto-mannite' and a condensationcatalyst selected from the group consisting of weak acids and acids-al-ts.

3. In a method of finishing a cellulosic mate-rial ineluding paper,cardboard, cotton, cellulose fabrics and the like, the improvementconsisting of coating said cellulosic material with about 0.1-7 gms. ofdry material per-square meter of cellulosic material of an aqueouscolloidal solution of a finish comprising 5-50 gms. of galacto-manniteper liter of solutionand .1- gms. of glyoxal per 100 gms. ofgalacto-mannite, and drying the product thus coated between about100-150 C. 4. A permanently finished cellulosic material having acellulose base, glyoxal residue condensed with the surface molecules ofsaid cellulose base, and galacto-mannite condensed on'said 'glyoxalresidue, said glyoxal. and galacto-mannite being present in an amount ofabout 0.1-7 gms. per square meter of ce'llulosic material.

References Cited by the Examiner UNITED STATES PATENTS 2,238,839 4/ 1941Watkins 8115.6 2,411,818 11/1946 Weiss 8-115.6 2,644,750 7/ 1953 Frischet a1 106-205 2,803,558 8/1957 Fronmuller 106--205 2,988,455 6/ 1961Rosenberg et al 106162 3,084,057 4/1963 Jordan 106-205 FOREIGN PATENTS634,634 3/ 1950 Great Britain.

ALEXANDER H. BRODMERKEL, Primary Examiner.

L. HAYES, Assistant Examiner.

1. A PERMANENT FINISH FOR CELLULOSIC MATERIALS CONSISTING ESSENTIALLY OFAN AQUEOUS SOLUTION OF COLLOIDAL GALACTOMANNITE HAVING A CONCENTRATIONBETWEEN 5 AND 50 GRAMS PER LITER OF SOLUTION AND A PROPORTION OF GLYOXALIN SAID SOLUTION BETWEEN 1 AND 50 GRAMS OF 100% GLYOXAL PER 100 GRAMS OFGALACTO-MANNITE.